Flushometers are a ubiquitous presence in most commercial restrooms, as well as in many homes. Flushometers typically utilize a familiar valve body having an inlet, an outlet, a handle opening, and a removable cap for accessing the valve. Thus, most flushometer valve bodies rely upon a four-port arrangement. Further, most such flushometers utilize a control stop associated with the valve body and positioned immediately upstream of the water supply, allowing the valve to be isolated from the water supply line by closing the control stop.
In-wall flushometers are known, but present a problem of access for maintenance and replacement. The four-port design requires a much larger freedom of access and working space than is typically available for in-wall or behind-wall installations. Further, the use of a control stop requires both a larger volume of area that must be accessed and further increases the mass of material that must be placed behind or in the wall.
In addition, flushometers in the art typically were designed for an environment where water conservation was not a consideration. Thus, a typical flushometer is not concerned with performance in a low flush volume environment, resulting in poor or undesirable performance of typical flush valves when put into service in a low flush volume environment. However, lower flush volumes exacerbate certain aspects of a flushometer's performance, such as a tendency to exhibit a harmful shock to the system upon opening and upon closing due to the abrupt change in flow. Further, the design of flushometer valves is such that if the valve fails, i.e. remains open, the valve is at its highest flow rate. This results in both a large amount of wasted water as well as an increased potential for an overflow from the associated toilet or urinal which may not be able to drain such a high flow rate when provided continuously.
Thus, there is a need for flushometers that provide for improved access in behind-the-wall or concealed applications.